An assembled battery configured of a plurality of lithium ion secondary batteries, is supplied with electrical energy outside the batteries when the remaining capacity becomes small. Namely, the assembled battery can be used repeatedly as a power source by storing electrical energy inside the batteries through charging.
As a charging method of the assembled battery, for example, an electric vehicle is charged by a charging stand exclusive therefor. Recently, the electric vehicle is also charged through a home outlet. Other than these, power supply methods at charging are known. Especially, a hybrid vehicle stores generated electric power through a generator which is operated by using motive power of a driving engine.
Recently, in the hybrid vehicle, the vehicle which is charged from a home outlet at parking is developed. Further, the vehicle can be charged by regenerative power generation at deceleration. A storage battery is mainly charged by electric power generated from renewable energy such as solar power generation, or wind power generation.
In the conventional assembled battery, the structure is known where a plurality of battery cells are arranged in series, and the periphery thereof is held by plate-shape members (refer to Patent Literature 1).
FIG. 6 shows a figure showing the conventional assembled battery described in Patent Literature 1.
In FIG. 6, a plurality of battery cells 2 are arranged at predetermined intervals in a stacked state such that large surfaces of the battery cells face each other. At both ends thereof, end plates 3 are disposed, and the two end plates are held by holder members 9 which face the side surfaces of battery cells 2. Battery cells 2 are swollen during charge-discharge, and then spaces between the cells or between the cells and the end plates become small. In order to suppress this, space maintaining members 10 are continuously connected in parallel.